1. Field of the Invention
This invention relates to an apparatus for producing a printing stencil plate for screen printing, and more specifically to an apparatus for sticking onto a screen plate a photosensitive laminated film obtained by forming a layer of a photosensitive agent on one surface of a base film.
2. Description of the Prior Art
A direct method and a direct/indirect method for producing a printing stencil plate (hereinafter simply referred to as "PS plate") for screen printing have been known. According to the former method, a photosensitive emulsion is applied onto the screen plate using a bucket squeegee followed by drying thereof The application and drying are repeated until a required thickness is obtained, in order to produce the PS plate.
The latter direct/indirect method can be divided into a water mounting direct/indirect method in which a layer of photosensitive agent on the photosensitive laminated film is swollen with water and is press-adhered onto a screen plate to produce the PS plate, and an emulsion mounting direct/indirect method in which a photosensitive laminated film and a screen plate are stuck together via a photosensitive agent of the film of the direct/indirect method and an emulsion of the same or a similar composition (hereinafter referred to as "mounting emulsion") to produce the PS plate.
With the water mounting direct/indirect method, however, the photosensitive agent of the photosensitive laminated film that is swollen is not applied to the back surface of the screen plate; i.e., the photosensitive laminated film is simply placed on one surface of the screen plate and exhibits poor resistance against the printing. With the emulsion mounting direct/indirect method, on the other hand, the mounting emulsion is applied even to the back surface of the screen plate. However, bubbles are easily introduced into the interface between the mounting emulsion and the photosensitive laminated film which deteriorates the adhesiveness as well as the resolving power.
To preclude such defects, it has heretofore been attempted to lower the viscosity of the mounting emulsion as done by the invention of, for example, Japanese Patent Laid-Open No. 114244/1986. When the solid content of the mounting emulsion is reduced to decrease the viscosity, however, the volume of the mounting emulsion greatly decreases after drying and the resistance against the printing is not much improved.